The present invention relates to a process cartridge and an electrophotographic image forming apparatus. In this specification, an electrophotographic image forming apparatus means such an apparatus that records images on recording media using an electrophotographic image formation system. The examples of electrophotographic image forming apparatuses include electrophotographic copying machines, electrophotographic printers (laser printers, LED printers, and the like), facsimile apparatuses, word processors, and the like.
A process cartridge is: a cartridge in which a charging means, a developing means or a cleaning means, and an electrophotographic photosensitive member, are integrally placed, and which is enabled to be removably installed in the main assembly of an image forming apparatus; a cartridge in which at least one among a charging means, a developing means, and a cleaning means, and an electrophotographic photosensitive member, are integrally placed, and which is enabled to be removably installed in the main assembly of an image forming apparatus; or a cartridge in which at least a developing means and an electrophotographic photosensitive member are integrally placed, and which is enabled to be removably installed in the main assembly of an image forming apparatus.
In the past, an electrophotographic image forming apparatus which employs an electrophotographic image forming process has been employing a process cartridge system, according to which an electrophotographic photosensitive member, and a single or plural processing means which act on the electrophotographic photosensitive member, are integrally placed in a cartridge removably installable in the main assembly of an image forming apparatus. This process cartridge system makes it possible for a user to maintain the apparatus without relying on maintenance personnel, drastically improving operational efficiency. Thus, the process cartridge system has been widely used in the field of image forming apparatuses.
A process cartridge is provided with an information storing means in which the history or specification values of the process cartridge care registered. The information storing means is enabled to communicate with the main assembly of an electrophotographic image forming apparatus so that the maintenance of the electrophotographic image forming apparatus main assembly and the process cartridge can be simplified or image quality can be improved. Some process cartridges are provided with a connector or the like which connects the electrophotographic image forming apparatus main assembly to the information storing means of the process cartridge. In order to eliminate the need for a mechanical connector which tends to increase the cartridge size, it has been considered to employ a noncontact communication system.
However, in the case of a process cartridge employing a wireless communication system, the aforementioned information storing means is affected by the electrical noises generated by the processing members, for example, a charge roller, a development sleeve, and a transfer roller of the apparatus main assembly, to which bias is applied from the electrophotographic image forming apparatus. Therefore, there is a chance that the contents of the information storing means will be destroyed or written over with erroneous information.
The present information is one of the results of the further development of the above described conventional technologies.
The primary object of the present invention is to provide a process cartridge enabled to wirelessly communicate with the main assembly of an electrophotographic image forming apparatus, and an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge capable of preventing the contents of the information storing means, which communicates with the main assembly of an electrophotographic image forming apparatus, from being destroyed or written over with erroneous information, and an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge in which an electrophotographic photosensitive drum is supported by a supporting means, and the information storing means is placed in the dead angle created by the electrophotographic photosensitive drum supporting means, as seen from any point on the linear interface between the charging means and the electrophotographic photosensitive means toward the photosensitive drum in a direction perpendicular to the longitudinal direction of the photosensitive drum, and an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge in which the information storing means is placed an the electrophotographic photosensitive drum side with respect to a plane, which is tangent to the peripheral surface of the electrophotographic photosensitive drum at the linear interface between the electrophotographic photosensitive drum and charging means, and is perpendicular to the longitudinal direction of the electrophotographic photosensitive drum, and also to provide an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge in which an information storing means is placed on the electrophotographic photosensitive drum side, with respect to a plane which is tangent to the peripheral surface of the electrophotographic photosensitive drum at the linear interface between the transferring means and electrophotographic photosensitive drum, and is perpendicular to the longitudinal direction of the electrophotographic photosensitive drum, and also to provide an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge in which the information storing means is placed on the electrophotographic photosensitive drum side, with respect to the plane which is tangent to the peripheral surface of the electrophotographic photosensitive drum at the linear interface between the electrophotographic photosensitive drum and developing means, and is perpendicular to the longitudinal direction of the electrophotographic photosensitive drum, and also to provide an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
Another object of the present invention is to provide a process cartridge in which the information storing means is placed outside a theoretical cylinder, the center line of which coincides with the axial line of the electrophotographic photosensitive drum, and which envelops the charging means, developing means, and transferring means, and also to provide an electrophotographic image forming apparatus in which such a process cartridge is removably installable.
These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.